Wobble plate laundry machine



April 22, 1958 T. R. SMITH WOBBLE PLATE LAUNDRY MACHINE 2 Sheets-Sheet 1Filed Dec. 27, 1955 lll wfi WQMWW Aw m m/ $6 f j' o o o o o o o o oApril 22, 1958 T. R. SMITH 2,831,333

WOBBLE PLATE LAUNDRY MACHINE Filed Dec. 27, 1955 2 Sheets-Sheet 2 o o oo o o o lo/ 0 o o o 95 9 94 o O O loq /0 o o o o /0 o o o 9/ I if; 0 o 0me 97 /05 72 8o 83 77 United States Patent WOBBLE PLATE LAUNDRY MACHINEThomas R. Smith, Newton, Iowa, assignor to The Maytag Company, Newton,Iowa, a corporation of Delaware Application December 27, 1955, SerialNo. 555,322

9 Claims. (Cl. 68-131) This invention relates to a wobble plate agitatorfor clothes washing machines. In the invention further disclosedhereinafter, a meniscus shaped agitator having a convex upper surfaceand a generally concave lower surface is provided with a dependingflexible sleeve molded integrally with the agitator proper. Thisflexible sleeve is clamped to certain bearing structure mounted in thebottom of a clothes basket enclosing the agitator to thereby form aliquid tight seal for an agitator power shaft journalled in that hearingstructure and provided with a bent terminal portion which extendsupwardly into the clothes basket through the resilient sleeve and into abearing formed in the agitator.

Rotation of the agitator power shaft in either direction causes theagitator to gyrate in a wobbling motion with its thinner peripheral rimmoving primarily in a vertical path and flexing in that direction toproduce a pumping action of the fluid within the clothes basket. Acleansing of the fabrics in the fluid is achieved by the toroidalcurrents generated around the agitator through this agitator movement.In the embodiment disclosed herein fluid is extracted from the clotheswithin the basket following the washing operation through a centrifugalextraction process by rotating a tubular spin shaft depending from theclothes basket and journalling the agitator power shaft.

While his recognized that agitators of the wobble plate type may berotated in either direction and require no gear trains or other motionconverting units necessary to achieve a reciprocating or oscillatingmotion now common to agitators of domestic type washing machines, thewobble plate agitator of this invention has further advantages. Thisagitator is preferably molded of one piece and not only provides thenecessary washing action required to properly cleanse fabrics but alsoprovides a liquid tight seal for the agitator shaft and its bearings toguarantee a service life free of damage caused by water seepage intothese parts. The agitator unit is simple in construction, effective inoperation and economical in manufacturing and assembly operations.

Through the use of the meniscus shaped agitator formed of a flexiblematerial, as further disclosed herein, an additional pumping action isachieved by the flexing of the peripheral rim of the agitator as itprogresses through its wobbling movement. These and other advantages,which will be more apparent when reference is made to the accompanyingdrawings and following description, form \the objects of this invention.

Referring now to the drawings:

Figure 1 is a sideelevation, partially in section, showing a washingmachine embodying my invention;

Figure 2 is an enlarged sectional view taken on line 2-2 of Figure 3 toshow the details of the agitator, the connection of the agitator powershaft to the agitator,

and the seal formed between the agitator and the bearing structurejournalling the agitator power shaft; and

Figure 3 is a plan view of the agitator taken on line 3-3 of Figure 1.

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In the accompanying drawings-there is shown a base frame 10 mounted onadjustable feet 11 and provided with a supporting dome 12 rising out ofa centrally located depression 13 in the base frame 10. Dome 12 servesas a mounting for a drive assembly 14 such as thatv disclosed in theJohn D. Goodlaxson application, Serial No. 505,231, filed May 2, 1955,and assigned to the same assignee as that of, the instant application.

Base frame member 10 also supports the upended reversible motor 15 andwater pump 16 which, like drive assembly 14, is driven by motor 15through belt 17 on the underside of base frame 10. Numeral 19 designatesthe groove of pulley 18 which serves as the input member for the driveassembly 14.

Cabinet 21, attached to and enclosing base frame 10 together with thedrive and tub assemblies supported thereby, is provided at its upper endwith a depending annular flange 22 defining an access opening into thewashing machine apparatus which is normally covered by access door 24.

In Figure 1 it can be seen that dome 12 in base frame 19 is providedwith friction pads 26 at its periphery adjacent the opening 27 in itsuppermost portion. I

An umbrella-like support member 28 rests on these friction pads 26 andis provided with three equally spaced ears 29 for three centeringsprings 31 which may be attached directly to base frame 10 or fastenedto brackets 32 connected to the base frame 10. This arrangement centerssupport member 28 on dome 12 and restrains it from rotation.

Threaded into the umbrella support member 28 is member 34 ofsubstantially frusto-conical configuration which serves as a housing fordrive assembly 14 of the previously identified Goodlaxson application,Serial No. 505,231. Housing member 34 cooperates with umbrella supportmember 28 by gripping the outer race ofa thrust bearing 35 which isprovided with a tapered inner race. Mating with and seated in thistapered inner race of bearing 35 is the spin tube or shaft 37 whichjournals a power shaft 38 also extending into the drive assembly 14.With this construction all weight placed on the spin tube 37, housing 34and on umbrella member 28 may be used to an advantage to provide amplefrictional forces between umbrella member 28 and the friction pads 26for dampening nutational movements of the shafts 37 and 38 relative todome 12 while permitting rotational movement of spin tube 37 in thrustbearing 35.

While the details of the Goodlaxson drive assembly forming the basis forthe previously identified application, Serial No. 505,231, are notessential to the construction of the instant invention, its operationcan be briefly explained for environmental purposes. Upon energizationof motor 15 in a direction to rotate pulley 18 in a counterclockwisedirection as viewed from the bottom of Figure 1, power shaft 38 isrotated in this same direction while spin shaft 37is held againstrotation by appropriate braking mechanism within housing 34. Uponreversal of motor 15, spin shaft 37 is released for rotation to allowboth of shafts 37 and 38 to be spun in unison in a clockwise direction.

With the drive and support construction set forth above, it can be seenthat shafts 37 and 38 may be selectively rotated as determined by thedirection of rotation imparted to pulley 18 While permitting theirnutation about a vertical axis at all times. In the modification setforth in the accompanying drawings, shafts 37 and 38 nutate on a pointdetermined by theintersection of the vertical axis of rotation with ahorizontalplane bisecting groove 19 of pulley 18.

With reference to the tub assembly enclosing the agitatorforming theinvention of the instant application, it

embodiment, "of channel-like cross section. Brace members 43 extendoutwardly and upwardly from umbrella support member 28 to join thenon-rotatable tub 44 through tub connectors 45to form an inverted tripodsupport "for tub 44. The tub 44 is provided with a bottom wall 47 inwhich is formed a C-shaped gutter 43 having its lowermost portionconverging into the drain outlet 45% which in turn communicates withwater pump 16 through the flexible drain hose 51.

The imperforate cylindrical side wall 52 of tub 44 includes a slightlyenlarged rim 53 on its uppermost portion before terminating in anoutwardly directed flange. Resting on the flanged upper edge of sidewall 52 is a spherical segmental member 55 having a flanged peripheryand a rolled inner edge. Member 55 forms a water tight seal with wall 52as these members are gripped by the rubber sealing band 56 encompassingthe peripheral flanges of wall 52 and the segmental member 55.

Resting on the upper surface of member 55 and having its innercylindrical portion fastened to the outer periphery of the dependingflange 22 is the combined water and vapor seal 58 which prevents theescape of either water or steam from tub 44 during normal use of themachine utilizing this construction.

Referring now to Figures 1 and 2 it can be seen that spin tube 37extends upwardly from drive assembly 14 and passes through the babbittbearing liner 61 on the self aligning bearing sleeve 62 which is fittedinto a centrally located flanged opening in the bottom wall 47 by asqueeze fit with a tubular rubber member 63 bonded to the periphery ofthe cylindrical sleeve 62 Sleeve 62 is provided with an annular oilreservoir 64 for the wicking material 65 which is fitted into the borescommunicating with the reservoir 64 and the spin tube 37 at the upperend of sleeve 62.

Since there is relative movement between the non-rotating tub 44 and thespin tube 37, tub 44 is provided with a bellows type seal 68 which ispressed'against the bottom wall 47 by means of a coil spring 69 withinthat seal. The uppermost portion of seal 68 is provided in turn with acarbon nosed sealing ring 71 which is pressed upwardly by the coilspring 69 against the lower side of a tubular basket mounting stem 72.

Basket mounting stem 72 slides onto the upper end of spin tube 37 and isheld in position on that tube by means of a pin 73 inserted in the upperend of spin tube 37. While the preferred construction utilizes twodiametrically opposed pins to hold the basket mounting stem 72 on shaft37, only one of these pinsis illustrated in Figure 2 in order tosimplify that drawing and to show more clearly the additional basketsupporting function of the mounting stem 72.

Basket mounting stem 72 includes a frusto-conical shoulder 77 whichsupports the basket 78 having a bottom wall 79 and a side wall 81.Bottom wall 79 is perforate at its lowest elevation for passage ofliquid and sediment into the tub 44 and has a slope conformingsubstantially to the bottom wall 47 of the outer tub 44. Side wall 81includes a main perforate cylindrical portion and an upper imperforateportion which slopes inwardly towards its axis of rotation to form aseat for balancing ring 82 within rim 53 before terminating in a rollededge 84 which defines the access opening into the tub assembly.

While the weight of basket 78 is supported on the mounting flange 77,basket '78 is prevented from tipping,

tilting or turning on that flange by means of the large nut 86 which isthreaded on the-upper part of the basket mounting stem 72 in order towedge the conical portion of wall 79 against the flange 77. In additionto wedging basket 78 on flange 77, nut forces the centrally locatedhorizontal flange 83 of basket 73 against a small sealing gasket 35located immediately below the latter flange to provide an air-tight sealbetween basket 78 and the basket mounting stem 72.

Referring now to the novel type agitator construction forming theinvention of this application, it will be noted that the agitator powershaft 38, which extends upwardly from the drive assembly 14, passesupwardly through a bearing 91 which is seated in the recessed upper endof spin tube 37. From bearing 91 power shaft 38 extends through a thrustcollar 92 fastened to power shaft 38 by means of a pin 3 to prevent anyaxial movement of that shaft in a downward direction. The terminalportion 94 of power shaftSh is bent slightly from the vertical axis andis journalled in a needle bearing95 housed within a bearing retainer 96which in turn is contained within a mating bore of the wobble plateagitator 97. Bearing disc 98 fitted into the upper end of bearingretainer 96 and abutting the end of shaft 38 prevents centralized wearon agitator 97 by rotation of that shaft.

Wobble plate agitator 97 is formed substantially in the shape. of ameniscus from rubber or a similar resilient material and has a convexupper surface 101 and a generally concave lower surface 102. Thesesurfaces 101 and 102 cooperate with each other to define a rather thickdurable central portion which encloses bearing retainer 96 as well asdefining a thinner more flexible rim 163.

Molded integrally with the main meniscus portion of agitator 97 is thesealing sleeve 104 which extends downwardly past the bearing retainer 96and well over the upper end of mounting stem 72 where it is mechanicallysealed by means of the clamp ring 105 encompassing the lower end ofsleeve 104. In the preferred embodiment illustrated sleeve 104 is moldedin a symmetrical mold with a preformed slightly bulbous section 106 toachieve a flexible bellows type action during the gyration of agitator97 upon the rotation of agitator power shaft 38.

In this embodiment the terminal shaft portion 94 is inclined slightlyfrom the vertical so that each revolution of power shaft 38 moves eachpart of the rim 103 through a small arc. Since most of the movement ofrim 103 is in a-vertical direction due to the slight lateral movement ofagitator 97, each point on rim 103 describes an ellipse having avertical major axis.

It is within the teaching of this invention to vary the inclination ofthe shaft portion 94 with respect to the vertical or to replace the bentshaft portion 94 with an offset crank in order to eliminate or reducethe lateral movement of agitator 97 or to. increase the verticaldisplacement of rim 103. It should be noted here that regardless of theinclination of shaft portion 94, shaft 38 and its bearings 91 and 95will be well protected from damage'from water seepage by means of theflexible sealingv sleeve 1&4.

In operation, over typical agitation and spin periods, the fabrics to becleaned are inserted into basket 78 through the access openings definedby depending flange 22 and the rolled edge 84. A suitable detergent isthen added to the water placed within the tub 44 by a water supplysystem not shown and not forming a part of this invention. Though avalve may be used in the drain hose 51 to prevent the washing fluidsfrom draining from the tub 44, the water may be retained within tub 44in this illustrated embodiment by merely maintaining the externaldrainhose (not shown) attached to the outlet of pump 16 at a higher elevationthan elevation of the water contained within tub 44.

During the tub filling period when the liquid rising within tub 44 hascovered the perforations in the sloping basket bottom wall 79, air willbe trapped between the bottom walls 79 and 47 due to the sealing actionof the bellows type seal 68 and the air-tight connection between basket78 and the basket mounting stem 72. This normally prevents fluids fromcontacting the bellows seal 68 or the carbon nose ring 71.

After tub 44 has been filled with the selected quantity of washingfluid, the reversible motor is then energized through a control system(not shown) to rotate the drive pulley 18 in a counterclockwisedirection as viewed from the bottom of Figure 1. Through the use of thedrive assembly illustrated, rotation of pulley 18 at a speed ofapproximately 600 R. P. M. in a counterclockwise direction imparts thesame angular velocity and directional rotation to power shaft 38 whilethe braking mechanism provided within the drive assembly 14 restrainsspin tube 37 against rotation with power shaft 38. From this, it will beapparent from Figure 2 that rotation of power shaft 38 causes the bentshaft portion 94 to move agitator 97 in a gyratory path while theanchoring clamp 105 which fastens the sealing sleeve 104 to the brakedstationary mounting stem 72 will restrain agitator 97 from rotation andcause it to assume a wobbling motion necessary to achieve the desiredwashing action.

For satisfactory washing action the water level within tub 44 shouldcover the upper surface 101 of agitator 97 to allow the water currentinducing the lower surface 102 to effectively propel the waterdownwardly and away from the underside of the agitator 97. Since thewater currents as set up by the wobbling agitator are strongest in theregion below and immediately around the agitator, a more vigorous andmore thorough washing action of the clothes in this zone is achievedthan has been gained in the past by earlier types of wobble plateagitators incorporating a shielded construction preventing clothes frombeing agitated in this zone.

The particular shape of agitator 97 is unique in that it produces fluidcurrents which go down and away from agitator 97 in a toroidal actionaround agitator 97. While rim 103 moves up and down in a primarilyvertical direction, the water currents generated by the movement ofagitator 97 are primarily unidirectional due to the use of the meniscusshaped agitator. This particular current path is achieved as the curvedupper surface 101 encounters less resistance in its upward travel thandoes the cup-like lower surface 102 in its downward travel during thewobbling movement of the agitator 97 Consequently, a greater pumpingaction results during the downward movement of rim 103 than during itsupward movement.

While the shape of the agitator 97 accounts for its novel pumpingfunction, the impulsing action may be accented through the use of aresilient material such as rubber or the like as illustrated in theaccompanying drawings. Such a resilient material allows the agitator rim103 to buckle downwardly and thus decrease the fluid propelling areawhen the rim 103 is moved upwardly whereas a downward movement of n'm103 causes the cup-like surface 102 to flex outwardly to a greaterdiameter to thereby increase the effective pumping area.

The wobhling action of agitator 97 forces the cleaning fluid through thefabrics within the basket 78 and separates impurities held by them. Thelarger and heavier particles such as sand and sediment fall to thebottom of the basket 78 where they pass through the holes in the bottombasket wall 79 in the lowermost portion of that wall. This agitation offluid within tub 44 also causes these heavier particles to work theirway down the sloping tub wall and into the gutter 48 around theperiphery of bottom Wall 47. Once in this gutter, these particlescontinue to seek a lower elevation in the agitator fiuid and eventuallyfind their way into the deepest.

part of gutter 48 where they pass into the drain outlet 49 and then intothe drain hose 51.

Upon completion of the agitation cycle and the initiation of the spin orliquid extraction period, motor 15 is reversed causing the water pump 16and the drive assembly pulley 18 to reverse their directions also. Whendriven in this direction, water pump 16 is permitted to pump the washingfluid together with the accumulation of sand and sediment from tub 44through its drain connections. This reversal of motor 15 also causes thebraking mechanism within drive assembly 14 to release the spin tube 37for rotation in unison with the power shaft 38. Rotation of the spintube 37 imparts a similar rotary movement to the basket mounting stem 72and consequently to the clothes basket 78 which centrifugally extractsfluids through its perforate side wall 81. While these rotating membersare maintained in balance above the critical speed of this apparatus bymeans of the balancing ring 82, it should be noted that the lateraldeviation of basket 78 with respect to the non-rotating outer tub 44 isprevented by means of the self-aligning radial bearing provided in thebottom of tub wall 47.

At the end of the spin dry operation motor 15 is stopped causing thedrive assembly 14 to quickly terminate the rotation of both of shafts 37and 38. Though these periods may be repeated and rinse'periods added,this terminates the spin period of an illustrated operational cycle.

While I have illustrated the operation of my novel type agitator incooperation with the tub assembly disclosed and with a specificreversible drive assembly, it should be realized that this agitator maybe used with other types of tub assemblies and need not be used with areversible drive assembly.

In summary then, it will be noted that the disclosed agitator provides asimple, economical and effective means for cleansing soiled fabrics. Iteliminates the conventional motion converting units necessary to achievea reciprocating or oscillating motion common to agitators now common indomestic type laundry machines and it is relatively simple tomanufacture, assemble and service. In addition, it incorporates a uniquesealing sleeve for sealing the agitator power shaft from any waterdamage.

While only one embodiment of my invention has been illustrated in theaccompanying drawings, it is deemed within the teaching of my inventionto invert the meniscus shaped agitator or to provide a multiple stackingof such agitator discs. Furthermore, it is realized that slightlydifferent wobbling movements may be obtained by the use of an offsetcrank rather than by the use of a bent shaft as illustrated in thisembodiment. It is therefore my intention not to be limited to thedisclosed embodiment but by the appended claims.

I claim:

1. A washing device comprising, a tub, first bearing means in said tub,a power shaft journalled in said first bearing means, a terminal portionon said shaft positioned in said tub in an oblique relationship to thelongitudinal axis of said shaft in said first bearing-means, means forturning said shaft, a wobble plate agitator within said tub, saidagitator having a central portion provided with second bearing meansreceiving said terminal portion, said agitator being further providedwith a sleeve formed integrally with said central portion in acontiguous relationship to said second bearing means and depending fromsaid central portion to provide a seal for said shaft and for said firstand second bearing means, and means anchoring said sleeve to restrainsaid agitator against turning with said shaft.

2. A washing device comprising, a tub, first bearing means in said tub,a power shaft journalled in said first bearing means, a terminal portionon said shaft positioned in said tub in an oblique relationship to therotational axis of said shaft in said first bearing means, means forrotating said shaft, a wobble plate agitator within said tub, saidagitator having a central portion provided with second bearing meansreceiving said terminal portion,

said agitator being further provided with a flexible sleeve formedintegrally with said central portion in a contiguous relationship tosaid second hearing means and depending from said central portion toform a liquid tight seal for said shaft and for said first and secondbearing means, and means anchoring said sleeve on said first bearingmeans to restrain said agitator from rotation with said shaft.

3. A washing device comprising, a tub, first bearing means in said tub,a power shaft journalled in said first bearing means, a terminal portionon said shaft positioned in said tub in an oblique relationship to therotational axis of said shaft in said first bearing means, means forrotating said shaft, a resilient one-piece wobble plate agitator withinsaid tub, said agitator having a central portion provided with secondbearing means receiving said terminal portion, said agitator beingfurther provided with a flexible sleeve formed integrally with saidagitator and in a contiguous relationship with said second bearingmeans, said sleeve depending from said central portion and anchored onsaid first bearing means to provide a water-tight seal for said shaftand said first and second bearing means and to restrain said agitatoragainst rotation with said shaft.

4. A washing device comprising, a tub, bearing means in said tub, apower shaft journalled in said bearing means, a terminal portion on saidshaft positioned in said tub in an oblique relationship to therotational axis of said shaft in said bearing means, means for rotatingsaid shaft, a resilient meniscus-shaped wobble plate agitator withinsaid tub, said agitator having a central portion with a bearingreceiving said terminal portion, said agitator being further providedwith a flexible sleeve formed integrally with said agitator, said sleevecooperating with said central portion to provide a mounting for saidbearing, said sleeve depending from said central portion to form awater-tight seal for said shaft and said bearing means, and meansanchoring said sleeve to restrain rotation of said agitator with saidshaft.

5. A Washing device comprising, a tub, bearing means in said tub, apower shaft journalled in said bearing means, a terminal portion on saidshaft positioned in said tub in an oblique relationship to therotational axis of said shaft in said bearing means, a meniscus-shapedwobble plate agitator within said tub, said agitator having convex andconcave surfaces cooperating with each other to define a central hubportion and a resilient peripheral rim, a bearing in said central hubportion receiving said terminal portion, said agitator being furtherprovided with a flexible sleeve formed integrally with said centralportion and depending therefrom to form a water-tight seal for saidshaft and said bearing means, said sleeve cooperating with said centralportion to provide a mounting for said bearing, means for rotating saidshaft in said bearing means to impart an undulating movement to saidagitator, and means anchoring said sleeve to restrain said agitatoragainst rotation with said shaft.

6. A washing device comprising, a tub, bearing means in said tub, apower shaft journalled in said bearing rim, ahearing in said central hubportion receiving said terminal portion, said agitator being furtherprovided with a flexible sleeve formed integrally with the said centralportion and depending therefrom tocover and seal said shaft and saidbearing means from fluid surrounding said agitator, said sleevecooperating with said central portion to provide a mounting for saidbearing, means for rotating said shaft in said bearing means to impartan undulating movement to said agitator and a flexing movement to saidrim, and means anchoring said sleeve on said hearing means to restrainsaid agitator against rotation with said shaft.

7. In a washing machine, a tub provided with a bean ing therein, ameniscus-shaped Wobble agitator positioned within said tub, a revolubleshaft journalled in said hearing and provided with a terminal portioninclined from the longitudinal axis of said bearing and extending intosaid tub, a hearing retainer sleeve mounted in said agitator, bearingmeans in said bearing retainer sleeve for receiving said terminalportion to effect a wobbling movement of said agitator during rotarymovement of said shaft, a flexible sealing sleeve joined to anddepending from said agitator toward said tub, said sealing sleevecontiguously encircling said bearing retainer sleeve and having adepending end encompassing said bearing in said tub to provide awatertight seal for said last named bearing.

8. In a washing machine, a tub provided with a bearing therein, ameniscus-shaped wobble agitator positioned within said tub, a revolubleshaft journalled in said hearing and provided with a terminal portioninclined from the longitudinal axis of said bearing and extending intosaid tub, said agitator including a central portion mounting a bearingretainer sleeve therein, bearing means in said bearing retainer sleevefor receiving said terminal portion to effect a wobbling movement ofsaid agitator during rotary movement of said shaft, said agitatorfurther including a flexible sealing sleeve contiguously encircling saidbearing retainer sleeve and having a depending end encompassing saidbearing in said tub to provide a water-tight seal for said last namedbearing.

9. In a washing machine, a tub provided with a hearing therein, a wobbleagitator positioned within said tub, a revoluble shaft journalled insaid bearing and provided with a terminal portion inclined from thelongitudinal axis of said bearing and extending into said tub, a rigidsleeve carried in said agitator for receiving said terminal portion toeffect a wobbling movement of said agitator during rotary movement ofsaid shaft, a flexible sealing sleeve joined to and depending from saidagitator toward said tub, said sealing sleeve contiguously encirclingsaid rigid sleeve and having a depending end encompassing said bearingto form a Watertight seal therefor.

References Cited in the file of this patent UNITED STATES PATENTS2,215,288 Hays Sept. 17, 1940 2,471,876 Kuhn May 31, 1949 2,554,573Johnson May 29, 1951 2,695,510 Clark Nov. 30, 1954 2,715,826 Kirby Aug.23, 1955 FOREIGN PATENTS 894,541 Germany Oct. 26, 1953

